Bending tool



NOV 4 A. STENSRUD BENDING TOOL Filed Feb. 19 1923 lijven 016.

Patented Nov. 4, 1924.

PATENT OFFICE.

ANDREW STENSRUD, 0F OAKLAND, CALIFORNIA.

BENDING root..

Application led February 19, 1923. Serial No. 620,029.

To all vvri/10m t may concern.'

Be it known that I, ANDREW STENSRUD, a citizen of the UnitedStates, and a resident of Oakland, county of Alameda, State of California, have invented a new anduseful Bending Tool, of which the foll'owing'is a specification.

-The present invention relates to improvements in means for bending or straightening connectingrods and its particular object is to provide a suitable tool that will allow a connecting rod to be bent while the same is fastened to the piston to secure perfect parallelism between the axes of the wrist pin and the crank shaft. After a connecting rod has been straightened out to approximately bring the two axes referred to into the proper relationship it frequently happens that there still exists a slight divergence between the two axes which can be remedied conveniently only while the connecting rod is in place since any attempt at bending 'the connecting rod into the proper shape while the same is disconnected from the piston might result in an excess bending in the opposite direction. My tool is designed to allow the finishing operation to be carried out while the connecting rod is in position whereby any error may be eliminated.

The preferred formI of my invention is illustrated in the accompanying drawing in which Figure 1 shows my tool attached to 'a connecting rod in an operative position, the piston being shown in section. Figure 2 a cross section taken along line 2-2 of Figure 1. Figure 3 a perspective detail view of my tool and Figure 4 a detail view of a connecting rod showing a somewhat exaggerated bend in the same which may be taken out by'means of my tool. While I have shown only the preferred form of the invention .it should be understood that various changes or modifications may be made within the scope of the claims hereto attached without departing from the spirit of my invention.

In Figure 4 is shown a situation calling for the use of my tool. The connecting rod (1) rotatably engaging at one end the 'wrist pin (2) and at the other end the crank pin (3) is slightly bent so that the axis (4) of the wrist pin is disposed at a slight angle to the axis (6) of the crank pin instead of being exactly parallel to the same. If this condition were allowed to exist in the assembled engine the piston of the engine would not aline with the cylinder but would occupy a slanting position within the same which again would have a tendency to score the inner wall of the cylinder thereby ren'- dering the engine ineflicient.v

Figure 1 shows my means for remedyig this condition. The crank pin bearing of the piston rod is engaged with a shaft (8)v which latter is rigidly supported by any suitable means as for instance by means of a vise well known in the art and therefore not illustrated in the drawing` The other end of the connecting rod is attached to its 4piston (9) in a well known mannergthat is, its bearing (11) engages the wrist pin (2) preyiously referred to which latter is supported 1n two oppositely arranged embossments (12) on the inside of the piston. If the connecting rod is in perfect condition the piston should be disposed exactly at right angles to the shaft (8) and whether this condition exists may be ascertained by any suitable means as Afor instance by the two squares (13) placed with one edge on the Shaft (8) so that their other edges lie against the surface of thepiston in the manner shown in Figure 1. If the rod is bent in the manner illustrated in Figure 4 the piston would be in a position relative to the two squares asindicated in dotted lines in Figure 1, that is the upper edge (14) would make contact with one of the squares only while the lower edge (16) would make contact with the other square, yand the two axes of the wrist pin and the shaft (8) which latter of course represents the crank pin or the crank shaft would converge slightly.

My tool for remedying this condition and for bringing the piston in exact parallel-relation with the twosquares comprises -a heavy plate (17) from which rise in spaced relation three projections (18), (19), and

(20). The plate is substantially triangular T in shape and its dimensions are such that it may be introduced into the open endof the piston. The projection (19) is preferably disposed at the extreme end of the plate so that it may be brought into engagement with the connecting rod at the point where it joins the bearing container (21). The projection (18) is disposed in a second corner of the triangle of the plate in such a manner that it engages the connecting rod on the opposite side at a longitudinal distance from the point of engagement with the first projection (19) when the base (22) of the triangular plate is substantially parallelto the connecting rod. It will be seen that in this manner a bending effect may be exercised on the connecting rod by swinging the eX- treme end of the plate to the right as viewed in Figure 1 which would cause the projection (18) to revolve about the point of engagement of the projection (19) with the connecting rod. This effect is obtained by means of the third projection (20.) which is disposed inthe third corner of the triangular plate which is adapted to engage the connecting rod on the same side as thepro'jection (19) but at a considerable longitudinal distance from the projection (18).l This projection (20) is threadedly engaged by a set screw (23) adapted to bear against the connecting rod as shownat (24) and to force the projection (20) away freinthe connecting rod when it is turned in the proper direction. n

The roperation of niy device will be readily understood from the foregoing description: After the connecting rod hasv been engaged with the piston and is ready for the final alinement its free end is engagedl with the shaft (8) and the latter is rigidly mounted in a vise not shown in the drawing. The two squares (13) are then placed on the 'shaft -(8) and their edges laid against the` outlines of the piston to ascertainwhether the same is disposed at right angles to the shaft (8). If any divergence vis noticed as shown in the dotted lines in Figure l my bending tool is introduced into the open end of the piston with the projection (19) engaging the extreme end of the connecting rod and the projection (18) engaging the other side of the connecting rod at a longitudinal distance from its extreme end. The set screw (23) is then turned until perfect alinement is obtained. When the piston en gages the two squares on both sides throughout its length it is in the proper position and the two axes (4) andV (6) of the wrist pin and of. the crank pin, the latter being represented by the shaft (8), must be parallel.

I claim t' e 1. A bending tool for a connecting rod comprising a base plate having projections rising from its face in triangular relation so as to form a bed for the connecting rod with the plate contacting the bottoni face, two

projections contacting one side thereof and the third projection contacting the other side, and means for forcing one of the two projections away from the connecting rod whereby a bending effect is obtained.

`2. A bending tool foi' a connecting i'od comprising a base plate having projections rising from its face in triangular relation so as to form a bed for the connecting rod with the plate contacting the bottoni face, two A projections contacting one side thereof and necting rod with the plate contacting the bottom face', two projections contacting one side thereof and the third projection contacting the other side, and means for forcing one of the two projections away from the connecting rod whereby a bending effect,

is obtained.

ANDREW STENSRUD. 

